<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
 title="Crash [@ DoDeletingFrameSubtree] after reloading a xul page a few times with display: -moz-popup and menuitem">
  <menuitem style="display: -moz-popup;">
    <box style="display: -moz-popup;">
      <box style="display: -moz-popup;"/>
    </box>
  </menuitem>
</window>